目的：比较强酸消解-离心富集-光镜检验法（方法A）、微波消解-滤膜富集-扫描电镜联用法（方法B）和微波消解-滤膜富集-光镜检验法（方法C）在硅藻检验中的效果，为法医学实验室选择硅藻检验方法提供参考。方法60份样本，随机分为3组，分别采用A、B、C三种方法处理，比较3种方法处理样本所需时间、消化程度和硅藻回收率。结果样本处理时间C法最短，其次是B法，A法耗时最长（P<0.05）。B法和C法对组织的消化程度比A法更彻底。硅藻总回收率B法最高，C法其次，A法最低（P<0.05）。硅藻种类回收率B法最高，C法其次，A法最低（P<0.05）。结论强酸消解-离心富集-光镜检验法的硅藻回收率低，易漏检长度小于40μm、含量低于1/5的硅藻；微波消解-滤膜富集-扫描电镜联用法硅藻回收率高、定性定量准确，适用于疑难案例的硅藻检验；微波消解-滤膜富集-光镜检验法处理样本时间短、硅藻回收率高、种类检出全，设备经济、操作简单、易于推广。%Objective To compare the efficacy of three methods for forensic diatom test, namely strong acid digestion-centrifuge enrichment-light microscopy (SD-CE-LM), microwave digestion-membrane filtration-automated scanning electron microscopy (MD-ME-SEM), and microwave digestion-membrane filtration-light microscopy (MD-MF-LM). Methods Sixty samples were randomly divided into 3 groups for diatom test using three methods, and the sample preparation time, degree of digestion and recovery rate of diatoms were compared. Results The sample preparation time was the shortest with MD-MF-LM and the longest with SD-CE-LM (P<0.05). MD-ME-SEM and MD-MF-LM allowed more thorough tissue digestion than SD-CE-LM. MD-ME-SEM resulted in the highest total recovery rate of diatom, followed by MD-MF-LM and then by SD-CE-LM (P<0.05);the recover rate of different diatom species was the highest with MD-ME-SEM, followed by MD-MF-LM and SD-CE-LM (P<0.05). Conclusion SD-CE-LM has a low recovery rate of diatoms especially for those with lengths shorter than 40μm or densities less than 1/5. With a high recovery rate and accuracy in diatom test, MD-ME-SEM is suitable for diagnosis of suspected drowning cases. MD-MF-LM is highly efficient, sensitive and convenient for forensic diatom test.
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